Hydrometer



Ju ne 13, 1939. YE. JOHNSON HYDROMETER Filed Jan. 12, 1938 Patented June 13, 1939 UNITED STATES PATENT OFFICE A. Morsbach,

Rockford, Ill.

Application January 12, 1938, Serial No. 184,507

Claims.

This invention has special reference to hydrometers of the type used for testing the antifreeze solution of automobile radiators, the electrolyte of storage batteries, and for like testing 5 purposes.

Considerable difliculty and inconvenience is occasioned with hydrometers of this type due to clouding of the walls'of the glass tube, which obscures the scale on the hydrometer float contained therein making it difficult and sometimes impossible to read the same. This clouding may be due to a number of causes, the most common being the accumulation of dirt or sediment on the walls and the precipitation of moisture thereon, the latter forming an opalescent film which obscures the scale.

An object of the invention is the provision of a hydrometer having means for clearing and wiping the tube immediately before or during use of the device to render the scale visible for reading.

Another object is the provision of a wiping device which may be installed in conventional hydrometers of the class described.

Other objects and advantages will become apparent from the following description and the accompanying drawing, in which Figure 1 is a side View of a hydrometer embodying my invention showing the wiper in the withdrawn position;

Fig. 2 is a section on the 1, and

Fig. 3 is a section similar to Fig. 2 showing the wiper in the inserted position.

In the embodiment of the invention herein shown I have employed the usual hydrometer including a glass tube designated generally by the numeral 4, a rubber bulb 5, and a rubber tip 6. These are of the type conventionally used in hydrometers for batteries and radiator solutions. The glass tube 4 has an annular bead T at its upper end, and the bulb 5 has a recess 8 in the neck thereof adapted to receive the bead 1 so as to make substantially an air-tight fit whereby when the bulb is compressed and released, fluid will be drawn into the glass tube 4 through the rubber tip 6. The lower end of the glass tube 4 also has a bead 9 primarily for the purpose of 50 protecting the end of the tube from breakage.

The rubber tip 5 commonly has a sleeve H receivable within the lower end of the glass tube 4, a flange l2 and a tube l3, all of the elements being molded integrally, the rubber tube l3 being adapted for insertion into the battery, the radialine 2--2 of Figure tor, or other liquid container upon which test is to be made.

Held within the container is a hydrometer float I4 having the usual bulb portion l5 and stem portion 16, the stem having suitable graduations 5 thereon as shown at IT. The bulb portion I 5 has the usual knob-like projections I8 spaced thereon to prevent the Wall of the bulb from adhering against the inner wall of the glass tube 4 and to keep the float free within the tube. 10 When the tube 4 is free ofliquid, the float seats with its bottom end against the rubber sleeve H as shown in Fig. 3, and when partially filled with liquid of a density within the range of the hydrometer floats in the liquid in the fashion shown in Fig. 2.

The elements heretofore described are intended to be those of the conventionalhydrometer and to include a tube for holding the hydrometer float and the fluid to be tested, a flexible means for'insertion into the liquid to be drawn into the tube, and a bulb for drawing the liquid into the tube, and it will be recognized that these elements may take a wide variety of shapes. In the use of devices of this kind,,as for example, '25 on radiator solutions, the inner walls of the tube Very soon become dirty because of the rusty. nature of the solution. Each time a test solu'-' tion is drawn into the glass tube a certain amount of this fine sediment stays on the walls of the tube until after a comparatively small number of tests it is impossible to see the scale on the stem [6. In addition to this difficulty, the hydrometer is used under conditions which further aggravate the situation. In other Words, the test solution is ordinarily warm or hot, whereas the outside atmosphere is cold so that on a'cold day as soon as the test solution is drawn into the tube the water vapor in the space above the level of the liquid in the tube precipitates in small drop 40 lets on the inner surface of the tube producing a foggy condition which renders it difiicult or impossible to read the graduations on the scale. Analogous conditions arise in the use of hydrom eters in other fields, and I have provided means for obviating these difficulties. I

A rod or stiff wire l9 passes through the end of the bulb 5 as shown at 2|, the opening in the bulb being smaller than the rod to produce a tight fit and provide a seal. The end of the rod is given suitable shape characteristics as. shown at 22 to facilitate its handling. The lower end of the rod is attached to a metal tube or sleeve designated generally by the numeral 23, the internal diameter of which is greater than the exthat the sleeve may passldownward over he stem ternal diameter of; the stem l6,-and the length of which is greater than the length of the stem so V 26. 'A circular squeegee member 21 of such diameter as to rest firmly against the inner walls of the tube 4 is positioned against the washer ,26 and held thereagainst by means of a washer 28,.

the washer 28 being held in place by the end I jecting through the end of said tube opposite .said flexiblemeans for manual actuation of the 7 portion 29 of the tube which is spun over to hold the V washers and squeegee element firmly together. It will be noted from Fig. 3'that the com-l binedlength of the'rod l9 and the sleeve 23 is such that when the Hydrometer floatlrests against the sleeve I I and the rod is forced downward until the ring 22 abuts against the bulb 5, the lower end 1 of thetub'e 23 will-approach the bulb I'5'but' will not come into contact therewith, whereby upon r'eci'procation'of; the red the squeegee element 21 may be brought from the upper end of the glass tube 4 to a point below the lower end of the scale I! but cannot be brought'sufiiciently low to break" the hydrometer float by'pressureagainst the, bulb 15. Where the hydrorneter tester is intended for H use on'radiatorsolutions the rod I9, the sleeve 23 I well known in the art.

and the washers 26 and 28 may be formed of sordinary steelor other metal butwhen intendedfor use 7 withbattery solutions these parts must, of course,

' accumulated 'dirt be wipedfrom the interior. of

' bodiment byway of illustration only, and I do the tube,- but the fog may be wiped therefrom at the moment of itsuse. It will be observed that my construction does not necessitateany change whateverin the conventionaljhydrometer partsl withthe exception that a small hole is punched at thepoint indicatedat'ZI for'th passage ofthe: rod l9 and consequently may be" embodied in conventional hydrometers without any change inithemolds employed in their manufacture. It

7 will-'also be observed that thewiper functions'to-v wipe the tube to: a point below the lowermostaposition or. the scale on the float, the stem passing through the wiper duringa porion of its movement. It will also be observed that when the rodis'withdrawnrto thepositionshown in- Flg. 2, no interferenceqto the operation of the" float is occasioned by the presence of the wiping mechanism since the stem may pass'up into the bulb 5 tea point beyond the lowermost graduationthreon; It willalso be noted that the metal "sle eve 23 further "servesto' space the squeegee member 2} so that thislmember cannot be withdrawn beyond the upper end'of the tube so that the wiper'can never become displaced. 7 r

I have shown and described the present emnot wish to be limited'except as required by the prior art and the scope of the appended claims, in Which I claim: V

1. A hydrometer comprising a transparent tube, flexible means at one end of the tube for insertion in a solution to be drawn into said tube, means for drawing liquid into said tube, a hydrometer float in the tubefor testing the liquid and a wiper contacting the. inner walls of said tube and adapted to encompass said float during a portion of the wiping operation, and reciprocable means connected to said wiper and prowiper' to wipe foreign matter from the inner surface of the tube;

2. A hydrometer' comprising a transparent tube, a bulb spanning one end of the tube to drawl i'quid therein, flexible means for insertion in a solution to be, drawn into said tube, la.;hy-

reciprocable means co-nnectedto said wiper. land 'drometer float :in said tube,..a'wiper annularly projectingthrough said bulb for actuation. of -the wiper .towipe the walls of said tube;- 7

3. The combination in a hydrometer of .a trans; parent tubefor holding fluidto be tested, flexible means at one end of said tube for insertion into a solution to be drawn into said tube, a bulb at the opposite end of said tube for drawing liquid into said tube, a hydrometer float in the ,lame

for; testing said liquid, a, wiperlbearing against thelinner walls of said tube, and, arro d. attached 7 to saidwiper and extending throughq said bulb for reciprocating. said wiper in thejtube to wipe foreign matter from thewallsthereof, i,

. 4. The combination in a hydrometer;of]a

flexible. means at one; end of said tube for insertion into a solution toob'e drawn intosaid tube, a bulb at theoppositeend of said tube ,fQ draws ing liquid into, said tube,..a hydrometer floatin 4c transparent tube for holding liquid to be tested;

the tube for. testing: saidliquid, alrod pextending transparenttube for holding fluid to. betested,

flexible means at one endqof said tube forminsertion into a solutionltobecdrawn into said tube',

"a bulb at the opposite end of said tube for drawing liquid into said tube, a hydrometer float in the tube for testing said liquid, a wiper bearing against the inner walls of saidtube; said wiper having a central opening for thepassage of the hydrometer float stem for movement of thew'ipr" o toa pointbelow the lowermost position of the scale on saidste'm, and a rod attached to said' wiper and extending through saidbulb for recip-' rocating the wiper in the tube. y EVAB Jo-HNsoN. 

